No, that wouldn't work. You need to stop the array and re-assemble it.
Though I guess that will be a challenge as it is presumably your root (and only) filesystem.
That puts you in a spot of bother... but I cannot see how you could do that as you cannot boot from RAID5 so you cannot have it as your only filesystem.
Maybe we need to rewind a bit... what exactly if your configuration of devices and arrays and filesystems and what do you boot off?